POS1385 INTERNATIONAL CONSENSUS FOR ULTRASOUND DEFINITIONS OF TENOSYNOVITIS IN JUVENILE IDIOPATHIC ARTHRITIS: RESULTS OF A DELPHI PROCESS
Authors: P. Collado, S. Lanni, O. De Lucia, P. Balint, S. Guillaume, C. Hernandez-Diaz, N. M. K. Sande, S. Magni-Manzoni, C. Malattia, V. Martire, L. Rossi-Semerano, J. Roth, T. Ting, P. Vega Fernandez, D. Windschall, M. A. D’agostino, E. Naredo
Journal: Annals of the Rheumatic Diseases (2022)

Background Musculoskeletal Ultrasonography (US) is a suitable tool for the clinical assessment in juvenile idiopathic arthritis (JIA). Recently US definitions for normal components of pediatric joints and synovitis have been developed by the OMERACT US working group. Currently this group is working on development and validation of US definition for tenosynovitis as it is also an essential prerequisite for the reliable use of this technology in the pediatric age group. Objectives To produce consensus-based definitions for US tenosynovitis in JIA through a Delphi process. Methods We undertook a Delphi process on US-defined tenosynovitis in children that consisted of two steps. As a prior systematic literature review showed that US anatomy of the tendons is similar to adults, a Delphi questionnaire was written based on the consensual definitions developed for and used in adults with rheumatoid arthritis [1, 2]. The Delphi questionnaire was sent to rheumatologists and pediatricians who perform pediatric US examination, asking them to rate their level of agreement with each statement of US-defined tenosynovitis. Group agreement was considered if ≥80% of responders scored an item as either 4 or 5. In the second step, the definitions were validated on 88 standardized US images displaying various degrees of tenosynovitis obtained from JIA patients at various ages. Tendons often involved in JIA were selected (foot and ankle tendons, hand and wrist tendons, bicep tendon.). US images of both normal and tenosynovitis elementary lesions were collected by the 18 experts participating in the OMERACT US task force on pediatric tenosynovitis. An agreement ≥70% was considered mandatory for accepting the definition as applicable in the rated image. Results The response rate was 75% (28 out of 37) from the first Delphi questionnaire. Strong group agreement (≥86%) was obtained for the US definitions tested. The response rate was 88.9% (16 out of 18) from the Web-exercise after four rounds. The final definitions were validated on still images for all tendons, except for the biceps tenosynovitis in the age group 2-4 years (the definitions of elementary lesions and the global definition of tenosynovitis) as no image was available for this location and age group. Despite not reaching group agreement after the second and the third round for the US-defined normal finger pulley in children aged 8 years and younger (roughly 68% and 69% respectively), it reached a score of 99.8% after the fourth round. Conclusion US definitions of tenosynovitis and its elementary components covering a wide pediatric age range were successfully developed through a Delphi questionnaire and validated in a web-based still images exercise. These results provide the basis for the standardized US assessment of tenosynovitis in clinical practice. References [1]Ultrasound in the assessment of tenosynovitis in juvenile idiopathic arthritis: systematic literature review. Collado P on behalf of the OMERACT Ultrasound Task Force. DOI: 10.1136/annrheumdis-2019-eular.3493 [2]Reliability of a consensus-based ultrasound score for tenosynovitis in rheumatoid arthritis. Naredo E on behalf of the OMERACT Ultrasound Task Force. Ann Rheum Dis 2013;72:1328 Acknowledgements AG Bruyn, L Terslev, S Jousse-Joulin, A Rodriguez, M Steiner, E Inarejos, P Bøyesen, K Misaki, A Iagnocco, B Marston, T Cazenave, P Mandl, A Bruns. Disclosure of Interests None declared